Chaser tripping means



Aug. 26, 1941. w. J. HOGG CHASER TRIPPING MEANS Filed Jan. 16, 1940 5 Sheets-Sheet l ATTORNEY.

Aug. 26, 1941. w. J. HOGG I 2,253,523

CHASER TRIPPING MEANS Filed Jan. 16, l940 5 Sheets-Sheet 2 r N L.

I I V 2- Mt 1|1l ii ii H E j! I] H W a w ATTORNEY.

Aug. 26, 1941. w. J. HOGG CHASER'TRIPPING MEANS Filed Jan. 16, 1940 5 Sheets-Sheet 5 I A A 1 VB TOR. BY

ATTORNEY.

Aug. 26, 1941. w. J. HOG G 2,253,523

. CHASER TRIPPING MEANS Filed Jan. 16, 1940 5 Sheets-Sheet 4 ATTORNEY.

Aug. 26, 1941..

w. J. HOGG CHASER TRIP PING MEANS Filed Jan. 16, 1940 5 Sheets- Sheet 5 I 1 VB TOR. BY i 7% 7/ I I I ATTORNEY.

Patented Aug. 26, 1941 CHASER TRIPPING; MEANS William J. Hogg', Cleveland, Ohio, assignor, to The National Acme Company, Cleveland, Ohio a corporation of Ohio Application Janu'aryjlG, 140,Serial No. 314,034

22 Claims. I ann -@145) This invention relates to threading tools, particularly to. taps adapted for threading pipes having a large diameter suchas oil well pipes, the object of the invention being to provide a collapsible or receding pipe tap having. improved tripping means simple in construction and efficient in operation.

The present improved tripping means may be used with certain forms of threading tools such as tapered thread forming dies having shiftable or expanding chasers but it is especially adapted for use with a collapsible receding pipe tap such as shown and described in Drissner et al. Patent 2,024,278 of December 17, 1935.- Therefore, a reference to that patnt, -it is believed, will be sufiicient for an understanding of the general construction and operation ofthe tap and, therefore, a detailed descriptionthereof will be unnecessary herein a I In the drawings accompanying and forming a part of this specification, Fig. 1 is a longitudinal sectional view of this improved pipe tap.

Fig. 2 is a longitudinal sectional view taken at right angles to that shown in Fig. I. I

Fig. 3 is a longitudinal sectional view of a part of the tap, illustrating one form of this improved tripping means and its adjusting means.

. Figs. 4, 5, 6 and Tare similar longitudinal sectional views illustrating different forms of thi tripping means and g Fig. 8 is a detailed sectional View of the latch. Similar characters of referenceindicate corresponding parts in the several views.

Before explaining in detail the present improvement and mode of operation thereof, I desire to have it understood that the invention is not limited to the details of construction and arrangement of parts illustrated inthe accompanying drawings since the invention is capable of other embodiments, and thatthe phraseology employed is for the purpose of description and notof limitation.

The tap is rotated by any suitable source of power and is fed forward in the usual waywith taps of this type although the work may be rotated relative to the tap. g

This improved tap, in the preferred form thereof, comprises a housing! within which is located a sleeve I and .withintln's sleeve is a sleeved body 2 having ahead detachably bolted slots 6 on the. inner ends, I of the sliding chaser blocks 8 located circularly around the hardened core-4 and carried at the forward end of the sleeved body v2. 1 ,The chaser blocks .8 are suitably supported in radialrecesses 9, of, the sleeved body head 2 for radial shiftable or sliding 'movement by the tapered core 4, being interlocked with the core in the; manner just described. Mounted upon each of the radially shiftable blocks 8 is a circular cutter or chaser It! in Fig. 1, while in Fig. 2, angular cutters are shown. Thetapered core 4 is interchangeable and 'is, therefore, detachable from the core member or shank 3, being suitably secured'thereto as by a bolt. By means of this interchangeable and detachable core 4, various sizes of cores may be used, thereby permitting any desired number of circular chasers (Fig. l) to be used. a As the sleeved body 2 is fed forward with its chasers Hi, the sleeve l is carried along and the chasers 10 are fed into the work or pipe to be threaded. On this sleeve I is attached aayoke (see'Fig. 1).' In this yoke 24 is located a swiveled disk 25 and in this'disk is mounted the end'of a lever 26, the inner end of which is turned round to fit into a hole in this swiveled disk 25. This lever has substantially the same construction, connections and operation as disclosed in the patent referred to and, therefore, it is unnecessary to describe'the same further herein. I The tripping means In'the patent referred to, the tripping means shown in detail in Fig. 6 comprised aspring latch M in engagement with the end of the adjusting ring 53 which wasutilized for diameter adjustment. In the present instance, the tripping means cooperates with the same adjusting ring 5;; threaded onto the sleeve l and secured in adjusted position by a lock nut 51. Inthatpatent however, the tripping means was operated when the block {9 contacted a dog 42 adjustable; in a slot 43' to vary the point of trippingrand when this contact took place, the 't'rip'plunger 41 was suddenly actuated to shift thelatch 44 out of engagement with the end of the adjusting ring 53 whereupon the coiled spring 54 drew back the core, thus collapsing the chasers. However, this sudden release of the tripping means has certain disadvantages which it isthe object of the present improvement to avoid and for this purpose, thepresent improvement is so designed that there is no sudden or 'shar'prelease' and, therefore, incidental shock to the mechanism as is the case in the patent referred to since the parts all remain in contact so that there is a gradual release of the parts thus avoiding that shock and jar which increases wear and is always detrimental to mechanisms of any kind especially as the absence of such shock or jar materially prolongs the life of any mechanism.

Therefore, to collapse the chasers out of the work when the required length of thread has been cut, the sleeved body 2 carries an improved spring actuated trip latch 44 having a roller 45 mounted on a pin 46 and cooperating with a trip plunger 41. In the patent above referred to, the latch 44 simply projected into engagement with the outer end of the adjusting ring 53 but in the present instance, it is a positive, doubleacting latch since it locks both sides of a projection 53 carried internally of the adjusting ring 53 as this projection 53 of the ring extends into a recess 44 of the latch so that both sides of the projection 53' are engaged by the latch, the rear side having a straight face cooperating with a similar face on the latch and the front side having an inclined face cooperating with a imilar face of the latch. Thus, the latch acts on both sides of the projection thereby providing a double acting positive lock for the adjusting ring and so looking the body 2 and sleeve I together during the cutting of the threads. It is the release of this latch by the means about to be described that effects the collapse of the cutters when the thread has been cut.

Cooperating with the roller 45 of the latch 44 is a cam-formed plunger slide 4'! carried in a recess of the body 2, the tapered or cammed end of which is in constant engagement with the latch roller. The rear tapered or cammed end of this cam plunger is also constantly in engagement with a roller 48 of an intermediate means shown as a swinging lever 49 pivoted in a recess of the body 2 and the shifting of this lever slides the cam plunger 41 endwise thus tripping and releasing the latch from the projection 53 of the adjusting ring 53, thereby permitting the coiled spring 54 to draw back the core and collapse the chasers.

Pivotally carried by the swinging lever 49 (Fig. 3) is an adjustable lever 56 located in position to engage a tapered cam 5| carried by the housmg l and which is fixed in position by a screw 42, which screw in the prior patent was adjustable to vary the timing of the tripping means but, in the present instance, this screw is fixed, no slot being provided for its adjustment and, therefore, the tapered cam 5| is also fixed, in Fig. 1.

As the lever 53, which is properly shaped to contact the tapered cam 5| gradually moves along or up the tapered or inclined surface of the cam 5|, the lever 49 and its roller 49 are gradually shifted to correspondingly shift the cam plunger 41 and thus gradually trip the latch 44.

For adjusting the parts to vary the time of trip, the lever 59 is provided with a screw 52, the adjustment of which accomplishes this result. The tapered cam 5! is provided with an opening 5 to facilitate access to and adjustment of this screw, the lever 50 being of greater width than the width of the opening 5| so that it will always be in contact with the tapered surface of the cam member 5|. Thus, as the tap is fed forward or as the work is fed toward the tap, the parts'50 and 5| will have a relative movement. If the tap is fed, the lever 50 moves along the tapered surface of the cam plate 5|. If the work is fed, the reverse of this operation takes place and so gradually shifts the lever 49 and, in the manner hereinbefore described, releases the latch from the adjusting ring 53.

In the forms shown in Figs, 4, 5, 6 and 7, the adjustment of the time of tripping is obtained by adjusting the cam plate 5| carrying the screw 42 and for which purpose an elongated slot 42' is provided in the housing In the form shown in Fig. 4, the latch and its cam plunger are similar to those just described but the intermediate means shown as a swinging pivoted lever 49a is not provided with the adjustable lever 5|] but is of integral construction and so shaped as to engage the adjustable cam plate 5|, a roller 48 carried by this lever engaging the cammed end of the plunger 41.

In the form shown in Fig. 5, the pivoted intermediate means shown as a swinging lever 49b is provided with a block 490 carrying a roller in engagement with the cam plate 5|, the plunger 4? and lever 49b having cooperating curved surfaces, thus eliminating the use of a roller at the end of the lever 4917.

In the form shown in Fig. 6, the intermediate means comprises a cam plate 41 pivotally connected to a link 49d which, in turn, is pivotally connected to a lever 49c pivoted within the recess of the body 2, thus forming a toggle connection and this lever 49c is provided with a roller 29) in engagement with the adjustable cam plate In Fig. '7, the cam member 41a swings instead of slides and is of extended construction, being pivoted at one end to the body 2 at the rear of the latch and extends through the latch which is provided with oppositely inclined cooperating surfaces 47b. This member carries at its opposite end a block 41b and roller 41c acting as the intermediate means to engage the adjustable cam plate 5| but the principle of operation is substantially the same, the parts always being in contact for the gradual shifting of the latch.

The several cam surfaces of the members 41, 41a and 5| will have sunicient inclination or taper gradually to perform the tripping of the latch and this taper may be very slight and at the end of the movement more abrupt if desired, the object being to have a slow taper cam so as to avoid shock to the parts.

From the foregoing, it will thus be seen that when the tap is fed into the work to cut a tapered thread, the tripping mechanism, the parts of which are in constant engagement with each other, will be slowly and gradually operated, gently to release the latch 44 from the adjusting ring 53 and when this is done, and which takes place at the end of the threading operation, the spring 54 will immediately retract the core with relation to the body and housings and collapse the chasers without any appreciable shock or jar to the operating mechanisms.

When the tap has cut the thread and the chasers or cutters have receded or collapsed out of the thread, the tap can be withdrawn from the pipe or coupling by the-usual means provided for that purpose and can'then be reset.

The pipe or coupling engaging ring 4|, Figs. 1 and 2, carried by the housing is of somewhat different form from that shown in the said patent but the taper adjusting and resetting means is substantially the same and, therefore, a description thereof is unnecessary herein.

It is to be understood that by describing in detail herein any particular form, structure or arrangement, it is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

Having thus explained the nature of my said invention and described a way of constructing and using the same, although Without attempting to set forth all of the forms in which it may be made or all of the modes of its use, I claim:

1. A threading tool having radially shiftable chasers and means for tripping the chasers relative to the Work and comprising a latch, a shiftable cam member operatively associated with and for releasing the latch, and a tapered member cooperating with an intermediate means for shifting said cam member.

2. The structure of claim 1 in which said tapered member is fixed.

3. The structure of claim 1 in which said tapered member is adjustable.

4. The structure of claim 1 in which all of said tripping means are in constant engagement with each other.

5. The structure of claim 1 in which all of said tripping means have a gradual constant engagement with each other.

6. The structure of claim 1 in which the intermediate means comprises a swinging lever cooperating with the shiftable cam and tapered members.

7 The structure of claim 1 in which the intermediate means comprises a swinging lever cooperating With the cam and tapered members and carries means for adjusting the time of tripping.

8. The structure of claim 1 in which the intermediate means comprises a swinging lever cooperating With the cam and tapered members and carries a lever having adjustable means for adjusting the tripping time.

9. The structure of claim 1 in which the shiftable cam member comprises a sliding cam-formed plunger and the intermediate means comprises a swinging lever cooperating therewith and in engagement with said tapered member.

10. The structure of claim 1 in which the cam member-comprises a sliding cam-formed plunger. the intermediate means comprises a swinging lever cooperating therewith and an adjustable lever carried by said swinging lever and in engagement with said tapered member.

11. The structure of claim 1 in which the cam member comprises a cam-formed plunger and the intermediate means comprises toggle means 00- and connected at its opposite end and cooperates with the tapered member for shifting the plunger.

13. The structure of claim 1 in which the cam member comprises a cam-formed plunger, the intermediate means comprises a swinging lever cooperating therewith, said plunger and layer having curved engaging faces. and the swinging lever has means for engaging the tapered member.

14. The structure of claim 1 in which the intermediate means comprises a swinging lever having a roller engagement with the cam member.

15. The structure of claim 1 in which the intermediate means comprises a swinging lever having a roller in engagement with one of said members.

16. The structure of claim 1 in which the shiftable cam member comprises a sliding member and the intermediate means comprises a swinging lever between the tapered member and said sliding cam member for shifting said cam member, and means carried by said swinging lever for adjusting the time of shifting the latch.

17. The structure of claim 1 in which the shiftable cam member comprises a sliding member and the intermediate means comprises a swinging lever between the tapered member and sliding cam member for shifting said cam member and pivoted means carried by said swinging lever and having an adjustable device for adjusting the time of shifting the latch.

18. The structure of claim 1 in which said tapered member is fixed and the shifta-ble cam member comprises a sliding member and the intermediate means comprises a swinging lever therebetween having adjustable means for engaging the fixed tapered member to vary the time of tripping the latch.

19. A threading tool having radially shiftable chasers and means for tripping the chasers relative to the work and including an adjustable ring and a spring actuated latch having a pair of cooperating simultaneously acting opposed faces for double locking said ring.

20. The structure of claim 19 in which said ring and latch have-one a projection and the other a recess forming said opposed faces for the reception of said. projection, one face of which is straight and the other inclined and cooperating with similar faces of the projection.

21. The structure of claim 19 in which said ring has an internal projection and the latch has a recess forming said opposed faces for the reception of said projection, one face of which is straight and the other inclined and cooperating with similar faces of the projection.

22. The structure of claim 1 in which the shiftable cam member comprises a swinging cam lever.

WILLIAM J. HOGG. 

